PNI CompassPoint V2Xe - Manual (Page 20)

V2Xe User Manual – May 2012 Page 18
After a request for data is sent, a time delay is required for processing and sampling.
The time delay required is relative to the period select value being used and is also
influenced by the strength of field being measured. With a period select value of 8
(/4096), a delay of approximately 50 msec is required. The delay proportionately
decreases with decreasing period select value.
The kGetData sequence should be:
Send kGetData.
Delay.
Push 1 byte out of V2Xe module.
Test the response byte for 0xAA (Sync Flag). If True, push data out. If False,
loop on delay.
kGetDataResp (frame ID 0x05)
The response to kGetData is kGetDataResp. The specific data fields that will be
output (ID 1, Value ID 1, etc.) should have been previously established by the
kSetDataComponents command frame. The sequence of the output data components
will match that set by kSetDataComponents.
Example: If heading and magnitude are set to be output per the kSetDataComponents
command, the payload would look like:
0x02
Heading ID ID Count
Payload
Heading Value
(Float32)
Magnitude
ID
Magnitude
Value (Float32)
0x05 359.9 0x06 0.50
ID Count
UInt8
Payload
ID Specific ID Specific ID Specific
Value ID 1 Value ID 2 Value ID 3 ID 1
UInt8
ID 2
UInt8
ID 3
UInt8